Análise de parâmetros de segurança e novas indicações em vitrectomia via pars plana de pequeno calibre

• Autor(a) principal: Machado, Leonardo Martins [UNIFESP]
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=3934650; http://repositorio.unifesp.br/handle/11600/48061
• topic: Vitrectomy; Retinal diseases; Surgery; Vitreous body; Surgery; Epiretinal membrane; Vitrectomia; Doenças retinianas/cirurgia; Corpo vítreo/cirurgia; Membrana epirretiniana

Objectives: The present study was developed in three parts that aimed the following: 1 ? To measure and compare the impact pressure values of the air jet from vitrectomy infusion cannulas of three different sizes (20, 23 and 25 gauge). 2 ? To correlate pre and intraoperative findings with postoperative results in patients undergoing small gauge pars plana vitrectomy (23 gauge) to treat epiretinal membranes with the double peeling technique. 3 ? To determine the efficacy and safety of the treatment for symptomatic posterior vitreous detachment through small gauge pars plana vitrectomy (23 gauge) in pseudophakic patients with multifocal intraocular lens. Methods: The first study consisted in an experimental research conducted in an engineering laboratory, in which the impact pressure of the air jet of the infusion cannulas was measured using a manual transducer and the values found were compared between groups (considering the 20 gauge the control group). In the following retrospective study, patients previously submitted to 23 gauge pars plana vitrectomy with removal of both the epiretinal membrane and the internal limiting membrane had data regarding preoperative (best-corrected visual acuity, optical coherence tomography, fluorescein angiography and fundus autofluorescence) and intraoperative evaluation (behavior of the internal limiting membrane after the epiretinal membrane peeling with separation in three groups: A ? Absent; B ? Intact; C ? Fragmented) collected to observe possible parameters related to the visual and anatomic outcomes. The last study was a prospective case series in which patients with multifocal intraocular lenses and complaining of symptoms related to posterior vitreous detachment were submitted to small gauge pars plana vitrectomy. Data regarding best-corrected visual acuity and a questionnaire of visual function related to quality of life were compared between the pre and postoperative periods. Possible intra and postoperative complications were also observed. Results: In the first study, the impact pressure measurements were similar between the 20 and 23 gauge groups, for all the infusion pressure values, but the 25 gauge group presented lower values. In the second study, patients with hiperautofluorescent exams were more prone to an increased retinal thickness reduction postoperatively. Patients in group A tended to have higher retinal thickness values. The third study showed a significant improvement in the postoperative visual acuity and questionnaire values. There were no complications in the intra and postoperative periods. Conclusions: The current line of research in the usage of small gauge pars plana vitrectomy resulted in the following conclusions: 1 ? The air jet impact pressure values were similar between 20 and 23 gauge instruments and both showed higher results than the smaller cannulas (25 gauge). 2 ? Patients with a predominant hiperautofluorescent signal showed a higher amount of retinal thickness reduction postoperatively. A system for intraoperative classification of the internal limiting membrane was proposed and may be useful for future surgical studies. 3 ? 23 gauge pars plana vitrectomy is a safe and effective method to reduce visual disturbances associated to symptomatic posterior vitreous detachment in patients with previous multifocal intraocular lens implants, due to the findings of this study, and may be useful for the clinical setting.